Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower; the description still adds meaningful operational context the annotations lack — live slot reads, the dangerous EOA-admin/no-timelock case it flags, plus pricing ($0.03/call), x402 payment on Base, the x-credit-token header, 1 free call/day, and no API key requirement.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loads the core question and the tool's purpose, then layers in the risk framing and payment mechanics. Efficient overall, though the pricing/call-mechanics tail is somewhat long relative to the diagnostic content.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, return values need no explanation, and the description adequately covers what is inspected, the key risk pattern flagged, and access/payment mechanics. Only the positioning against overlapping ownership/authority tools is left implicit.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% for the single 'address' parameter, so the schema carries the burden. 'Required input: address' adds nothing beyond confirming requiredness, making the baseline 3 correct.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a precise verb+resource: reads EIP-1967 proxy slots to determine upgradeability, current implementation, and who holds upgrade authority. This is highly specific and clearly distinguishable from broader siblings like contract_info, contract_owner, or owner_powers.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description frames the use case well ('Upgradeability is a rug vector static scans miss'), implying it belongs in a contract due-diligence flow, but it never names alternatives or states when NOT to use it. Overlapping siblings such as owner_powers, contract_owner, and contract_danger are not addressed.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.